Ignition apparatus



May 9, 1933. Q H DAVlS, JR' y I 1,907,516

IGNITION APPARATUS Filed April 28, 1932 2 Smets-sheet 1 122i Q l" M I .pacedsed May9,1933. @HDM/lam 1,907,516

IGNITION APPARATUS Filed April 28, 1952 2 Sheets-Sheet 2 Patented May 9, 1933 UNITED STATES PATENT OFFICE CHARLES H. DAVIS, JB., DECEASED, LATEl OF ANDERSON, INDIANA., BY JOHN T.

FITZSIMMONS, ADMINISTRATOR, 01E.V ANDERSON, INDIANA, ASSIGNOR TO DEMO- REMY CORPORATION, OF ANDERSON, INDIANA., A CORPORATION OF DELAWARE IGNITION APPARATUS Applicationled April 28,

This invention relates to ignition apparatus for internal combustion 'engines and more particularly to engines which operate at relatively high speed and which require that a plurality of sparking impulses be provided simultanenously during each instant or period of power impulse.

' It is one of the objects of the present invent-ion to provide ignition apparatus for engines of the type referredto and this object is accomplished in the disclosed embodiment of the invention by novel distributing means operating in conjunction with sparking impulse generating means comprising a plurality of alternately operated generators each providing simultaneously a plurality of sparking impulses. The ignition distributor comprises a head carrying a circular row of posts to which the various spark gaps of the engine are connected and a rotor carrying a plurality of distributing conductors each of which is provided with an arm which moves past the row of spark plug posts of the distributor and each of which is provided with a plurality of branches s constructed and arranged as to cooperate alternately with other terminal posts connected with th sparking impulse generators.

Further objects and advantages oi the present invention will he apparent :trom the following description, reference being had to the accompanying drawings wherein-a preerred embodiment of one form of the present invention is clearly shown.

ln the drawings:

Figs. l and 2 together constitute awiring diagram illustrating the present invention applied to an S-cylinder 'double spark engine.

Figs. 3 and 4 together constitute a Wiring diagram illustrating the present invention applied to a l2-cylinder double spark engine.

Referring to Fig. l the circles niunered l to 8 respectively, represent the cylinder of an 8 cylinder engine. Each cylinder is provided with a plurality of spark gaps A and B. The manner of connecting these spark gaps with the ignitionapparatus is indicated by symbols rather than lines in order to avoid coni fusion of the diagram as shown in Fig. 2 which will now be described.

1932. Serial No. 607,926.

The battery is grounded at 2l and is connected by a switch 22 with a Wire 23 which leads to sparking impulse generators 24 and 34. The generator 24 comprises primaries P3 and P4 cooperating with secondaries S3 55 and S4, respectively. The generator 34 com` prises ignition coils having primaries Pl and P2 cooperating respectively with secondaries Sl and S2. l

rlhe primaries P3 and P4 are connected in 6@ series with battery 20 and with a terminal 25 of an ignition timer. Terminal 25 is connected by lea spring conductor 26 with a lever 27 pivoted at 28 and carrying a rubbing bloclr 29 Which cooperates with an ignition timer @5 cam 30. liever 27 carries contact 31 cooperating with grounded contact 32. Terminal 25 is connected with condenser 33.

Primaries Pl and P2 are connected with terminal of an. ignition timer. Terminal 'm 35 is connected by leaf spring conductor 36 with lever 37 pivoted at 38 and carrying a rubbing block 39 which cooperates iviththe cam 30. `Lever 3'? carries a contact cooperating ivith a grounded Contact 42. rller- 75 minal 35 is connected with a. condenser 43.

The cani 30 is driven by a shaft 45 which rotates at one-half engine speed for aour cycle engine or at engine speed :tor a two cycle engine. The shaft rotates a distribn- 80' tor rotor carrying segmentsl and 52 having arms 53 and 54? respectively, jivln'ch move inA proximity to a row of posts 55 each of which is connected with an engine spari; gap or spark plug in a manner to be described later. @Q Rotor 51 serves the A spark gaps and rotor 52 serves the B spark gaps.

The rotor 52 has branches R2 and R4 which are located in the same plane and Whichmove in proximity to distributor posts 56:,1'1IS1 and 9@ 5#S2 which are located diametrically opposite eachother and which are connected by Wires 6l and 62 respectively, with terminals of the secondary coils Sl and S2, respectively. The rotorV 52 is provided with branches R6 95 and R8 which alternate With the branches R2 and R4 and which terminate in projections extending into a plane other than and preierably above the plane of the branches R2 and R4. These rotor branches R6 and R8 move ma lbranches R1 and REE-cooperating with distributor posts 56:#:S1 and 56:,t/:S2. The branches R1 and R3 alternate with branches R5 and R7 which are locatedin the same plane as the branches R6 and R8 and which cooperate wtih the posts 57 #S3 and 57 #S4 .It will be noted that the two posts 56 connected to the sparking impulse generator 34 Vare diametrically opposite each other; and

that tne two posts 57 connected with generator 24 are diametrically opposite. The pairs of posts 56 and 57 are angularly related depending on the number of engine cylinders as will be explained later.- For an eight cylinder engine the angle is 90. It will be noted that the rotor arms R1 and R2 are diametrically opposite and likewise R5 and R6, R3 and R4, and R7 and R8; and considering all of these arms together they are spaced angularly Assuming that cam 30 rotates clockwlse, 1t will be noted that contact 41 is about to be separated from Contact 42 thereby effecting the discharge of the generator'34l including secondaries S1 and S2 from which sparking impulses will bedelivered to the pOSts 56#S1 and 56#S2. Fromthese posts the sparking impulses are conducted respectiyely, by rotor branches R1 and R2 to distrlbutor arms 53 and 54 respectively, and

40 thence to posts lA-'Sl-eRl and 1B-S2-R2.

The indicia lA-Sl-Rl indicates that spark plug A of cylinder 1 is provided with a sparkmg lmpulse by secondary S1 and that this sparking impulse is distributed through rotor branch R1. Similarly the indicia 1B-S2- R2 indicates that spark plug B of cylinder 1 1s provided with a'swparlng impulse by secondary S2 and that this sparking impulse is delivered through, rotor branch R2. lThe other indicia applied to other posts can easily be understood with this explantion.

When the cam 30 has rotated 45 from the position shown in Fig. 2 the rotor arms 53 and 54 will be moved adjacent' posts rotor branches R5 and R6 will be moved adv `jacent posts.57#S3 and 57:#:S4 respectively.

"05 to spark plug posts 55#2A-S3-R5 and 55:#:2B--S4-R6 respectively. 45 further,

rotation -o'f the. cam 30 will cause the contacts 41 and 42 to separate to discharge the generator 34, and the rotor segments R3 and R4 in conjunction with posts 56:#:S2 and 56#S1, respectively, will cooperate to conduct the sparking impulses. After another 45 movement of the cam 30' the rotorbranches R7 and R8 will cooperate with posts 57#S4 and 57#S3, respectively, to distribute sparking impulses generated by generator 24'the discharge of which is controlled by the opening of contacts 31 and 32. Thus far has been described the, operations which take place during one-half of the engine cycle or during onehalf revolution of the shaft 45. Obviously, a similar succession of events will take place during the other haltl of the revolution of shaft 45 or during the remainder of the engine cycle. This should be apparent since,

Vafter one-half revolution of shaft 45, the

rotors `51 and 52 will have exchanged places with respect to the position shown in Fig. 2.

It is therefore apparent that. the present invention contemplates the iuse of a plurality of sparking impulse generators which are operated alternately to discharge a plurality of sparking impulses which are discharged simultaneously to provide the required number of sparking impulses during each explosion period.- In the example given for an 8 cylinder engine having two spark gaps per cylinder and o erating at relatively high speed, two spar ing impulse generators are required to operate alternately in order tha-t one generator may accumulate energy while the other is discharging. AEach generator provides two sparking impulses through its secondary coils. Each generator might use a single secondary coili with both ends-insu lated and connected to a' pair of posts 56 or 5 o The invention contemplates the use of as many distributor rotors as there are sparking y an arm extending into proximity to a circular row of posts which are connected respectively with spark gaps. Each distributor rotor has a plurality of branches cooperating in recurrent sequence only with distributor posts connected with one o the sparking impulse generators, said branches alternating, with a plurality of other branches which cooperate in recurrent sequence only with distributor posts connected with'the other sparking imllb A pulse generator. For example, the rotor 51 has the branchesRl and R3 which cooperate only with the posts 56 connected with the generator 34; and these branches \R1 and R3 alternate with branches R5 and R7 -which cooperate only with posts 57 connected with generator 24. Similarly, the rotor 52 has branches R2 and R4 cooperating only with posts 56 connected withv generator 34 and isi these branches Rl and R2 alternate with branches R6 and R8 which cooperate only with posts 57 connected with generator 24.

lt will be understood that the present invention is not limited to ignition for an 8 cylinder engine having two gaps tired simultaneously at each explosion period but may be applied to engines having other numbers of cylinders, for example a 12-cylinder engine the ignition wiring diagram for which is shown in Figs. 3 and 4. For a l2-cylinder engine` the ignit-ion system using two sparkinipulses generators .tiring alternately, as `or an S-cylinder engine, will require a 6 lobe cam 30. lt is therefore apparent that the number of cam lobes must be one-half N, the number of engine cylinders. For a 12-cylinder engine the number of spark gap posts is obviously 24 or twice the number of engine cylinders. As shown in Fig. 4, the total number of rotor branches is 12, that is, equal to N, the number of engine cylinders. Each rotor carries N/2 or 6 branches. The spacing of the branches is 360 /N or 30 for a 12 cylinder engine.

Referring to Figs. 2 and 4 it will be noted that the angular spacing of posts 56 with respect to posts 57 is an even number times the angular spacing of the rotor branches. F or S-Cylinder ignition as shown in Fig. 2, the angular spacing of posts 56 and 57 is 2- times 45 or 90. `For 12-cylinder ignition as shown in Fig. 4, the angular spacing of posts 56 and 57 is 2 times 30 or 60. lt is quite obvious that the angular spacing of posts 56 and 57 could be an even number times the angular spacing of the rotor branches; however, the only angular measurements of interest are those which equal 90 or less, since there are `four posts 56 and 57 to be considered.

The following table shows numbers and a rangement of parts of the distributor for engines having various numbers of cylinders or Xplosion periods and requirmg the tiring or" two spark gaps at each explosion period.

Spacing of posts 56 and 57=2 or 4 times the rotor branch spacing, but not more than Q00 Cylinders or explosion periods per cycle Total 'rotor branches Rotor branch spacing y In each case set forth in this table, it is understood that two rotors are required and that each rotor must have an even number of branches, since the branches of each rotor must be divisible into two equal groups, the

branches of one group operating alternately with the branches' of another group. Therefore the total number of rotor branches must be divisible by four, hence the number N, of cylinder or explosion periods per cycle must be divisible by four. In other words, while the present-invention can be applied to double gap ignition for 8, 12, 16, 20, and 24 cylinder engines, it does not apply to 6, 10, 14, i8, etc., cylinder engines or to engines having odd numbers of cylinders.

`While the form of embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the-claims which follow.

What is claimed is as follows:

1. Ignition apparatus for an internal combustion engine having N cylinders or eX- plosion periods per cycle, N being a number divisible by 4, and requiring the firing of two spark gaps at each explosion period, said apparatus comprising, in combination, a distributor head having 2N posts arranged in a circular row and connected respectively with spark gaps, and hav'ng two pairs of. diametrically opposite spar ing impulse generator terminal posts, coaxial with the spark .gap posts, sparking impulse generating means, means operated by the engine for 'causing the sparking impulse generating means to deliver :sparking impulses alternately to said pairs of posts, and two engine operated rotor conductors each having a main arm cooperating with alternate spark gap posts of the head and each having N/2 branches angularly spaced 360o/N, alternate branches ofeach rotor conductor forming a group of branches which cooperate only with the posts of one pair of sparking impulse generator terminal posts, the remaining alternate branches of each rotor conductor torming a group of branches which cooperate only with the post of the other pair ot sparking impulse generator terminal posts, the angular spacing of said pairs of sparking impulse generator terminal posts being two or four times 360o/N, the angle being not more than 90.

2. lgnition apparatus comprising, in combination, a plurality of sparking impulse generators each capable of generating a plurality of sparking impulses simultaneously;

means for causing the generators to operate alternately; and a distributor comprising a head carrying posts connected with the spark gaps of engine cylinders and posts connected respectively with terminals of the sparking impulse generators, and a Vrotor carrying av plurality of distributing conductors, each conductor having an arm for distribution to certain ones of the spark gap posts of the head and each conductor having a plurality of collecting arms which cooperate only with the osts connected -`with terminals of one spar g impulse generator and each conducinl ,nately; and a distributor comprising a head carrying posts connected with the spark (gaps of engine cylinders and posts cpnnecte respectively with terminals of the sparking impulse generators, one set of posts` .being located at a greater distance from the axis of the head and terminating in a plane spaced substantially from the plane of the ends of the posts located at a lesser vdistance from the axis of the head, and a rotor carrying a plu` rality of distributing conductors, 'each contion engines ha ductor having an arm for distribution-to certain ones ofthe spark gap posts of the head and each conductor having a plurality of collectin arms which cooperate only with the posts ocated at the lesser .distance from the axis of the head and each conductor having a plurality of other'collecting arms alternating with the first mentioned collecting arms, said last mentioned collecting arms cooperatin only with `the posts located at the greater 'stance from the axis of the head.

4. Ignition apparatus for internal combusa plurality of explosion periods and requiring the irin of a plurality lof spark -gaps at' each expI l comprising, in combination, sparking impulse generating means controlled by the engine, a distributor head having circularly arranged posts. connected respectively with spark gaps and having other posts arranged concentrically of the Y spark gap posts and connected to the spark generator means and spaced at different distances from'the center of the head and distributing conductor arms passing between the spark gap posts and the vspark generator posts and each having a plurality of branches of different lengths, the longer branches cooperating with spark generator posts closer to the center of the head and the shorter branches cooperating with spark generator posts 'further from` the center of the head.

5. Ignition apparatus for internal combustion engines having a plurality of explosion periods and requiring the rin olfa plurality of spark gaps at each explosion periodcomprising, in combination.v sparking impulse generating means controlled by the engine, a distributor h ead aving circularly arranged posts connected respectively with spark gaps and having other posts arranged concentrically of the spark gap posts and connected to the spark generating means and o sion period -spaced atdiierent distances from thelcenter of the head, and distributing conductor arms passing between the spark gap posts and the spark generator postsand each having a plu-l rality of longer branches alternating with a plurality of shorter branches, the longer branches cooperating withL spark generator posts closer to the center of the head and the shorter branches cooperating with spark generator posts further from the center of the head. v

6. Ignition apparatus for internal combustion engines having a plurality of explosion periods and requiring the firing of a plurality of spark gaps at each explosion period comprising, in combination, sparkin pulse generating means controlled by t e engine, a distributor head having circularly arranged posts connected respectively with spark gaps and having other posts arranged concentrically of the spark gap posts and connected' to the spark generating means and,

rality of longer branches alternating with n a plurality of shorter branches, the longer branches cooperating with spark generator posts closer to the center of the head and the shorterbranches cooperating with spark gen- -eratorl posts further from the center of the head,and all of the branches being equi-angularly spaced b an amount equal to 360fdegrecs divided liy the total number of arms of all the branches.

7. Ignition apparatus for internal combustion engines having a plurality of explosion periods and requirin the firing of a plurality of spark gaps at eac explosion period comprising, in combination, a plurality of spark-- ing impulse generating devices controlled for alternate operation by the engine, and a distributor having circularly arranged posts connected respectively with spark gaps and 4having kother posts arranged4 diametrically opposite in pairs and concentrically with respect to the spark gap posts, the posts of one pair of diametrically opposite posts being located at a greater distance from the center of the head and connected with one sparking impulse generating device, and the posts of anotherl pair of diametrically opposite posts being located at a lesser distance from the center of the head and connected with another sparking impulse generating device,

and a-plurality of distributing conductor with spark generator posts closer to the center of the head.

'8. Apparatus according to claim 7 which' mem 1e the longer branches alternate with the sherer branches and the longer and shorer branches of one arm are respectively opposite the longer and short branches of another arm.

9. Apparatus according to claim in which the longer branches alternate with the sh0rt-` er branches and the longer and shorter branches of one arm are respectively opposite the longer and short branches of another arm and in which the branches are equiangularly spaced hy an angie of 360 degrees divided bythe tota number of branches of all the arms.

In tesnimony whereof is hereto axed the signature of JGHN T. FXTZSMMONS, Admzm'stratw of #ze Esta-te of Charles H.

Davis, Jr., Deceased.V 

